Purification and physicochemical characterization of human alpha 2-HS-glycoprotein

A large-scale purification method for alpha 2 HS-glycoprotein from normal human pooled serum is presented. 130 mg of alpha 2 HS was obtained from 21 of normal serum and the yield was 13.6%. Charge heterogeneity on isoelectrofocusing of this protein is mainly due to sialic acid. By the measurement of the circular dichroism spectrum, the alpha-helix content was calculated as 11% and the beta-structure content was calculated as 21 to 33%. alpha 2HS consists of a single polypeptide chain (Mr 49,000) of which the N-terminal amino acid is alanine. The N-terminal sequence of 31 amino acids contains 19 hydrophobic residues.